The Mist
by islamsayyid
Summary: Issei was killed and betrayed by the first women he ever dated. This in return reawaken a war between the fallen and one of the four riders of the Apocalypse. Issei OP. no devil transformation here folks
1. Chapter 1

I don't own high school DXD or monster hunter world.

Man monster hunter world is AMAZING! The graphics, the textures, the monster, the game play. ITS SO GOOOOOD. WHY DIDN'T THIS GAME COME OUT FASTER! But not like I can't complain I played for at least 140 hours. NO REGRETS! And because of that here I will release this base on my new favorite Elder dragon Val Hazaak. Enjoy.

* * *

 **Prologue: the Mist**

 **Kuoh Park**

It was a nice sunny afternoon perfect for a date. Which Issei thought as he had his first date ever with a beautiful perfect hourglass body name Yumma-chan. That was until she showed her true colors and revealed that she was a fallen angel. And that she was only toying with the perverts heart and killing him with a light spear.

After the Deed the Fallen than flown away but before saying one last thing "It was fun Issei. Even if it was the most boring time in my life. Seriously didn't it seem weird that a girl would actually like you? But That's why you will die as a pathetic virgin right here and right now. HAHAHAHAHAHHAHAHAHAHHAHAHAHAHAHAHHAHAHAHAHAHHAHAA"

Issei barley conscious heard everything and began shedding tears. Sure he was a pervert that peeks into girls changing lockers or talk openly about breast or how he wants to build a harem. But was that really enough of a crime for him to suffer both having his hearth being rip out of his chest by the girl he genuinely had affections for both figuratively and literally. No, it wasn't, that what Issei and the being residing in his body thought.

" **You didn't deserve this, my host. No, you didn't. But don't worry I won't let you die here and I shall kill those who were responsible for your suffering**." Was what a voice said creepily inside our dying pervert head before he lost consciousness.

Than dying Issei body began to emit a thick brown fog which first began enveloping the park. With devastating results first the ground began to spilt and dry up. Then the lakes, ponds and rivers water starter to boil and turn acidic which killed all of the aquatic wildlife that resides in them. The plants in the park were not in good shape either. Instead of dying the fog began to mutate them. Making the once beautiful flowers become ugly and deform, and the trees well all of their lush green leaves were now gone and replaced with weird pods that ooze out a deadly purple poison.

Luckily no Humans were harm by the mist. As the fallen had cast a ward in the park to ensure that no humans would come and witness the murder. This ward, however, did not work on the animal. So the stray dog, insects, reptiles, and birds were all present when the mist hit them. Which at first did do anything to them

But After the brown fog finished terraforming the park into a wasteland. The mist then began to mutate them first were the dogs. Which began to shed their fur leaving behind their bare skin which started to deform and resemble muscle tissue which was pinkish in color. It then grew in size roughly to the size and hight of a rhino but was much more linear and faster. In each paw grew an extra pair of long claws which was sharp enough to cut through steel also it grew bone-like protrusions sprouting from its back and tail. These beasts were called Odogaron and they are known in the underworld to spread a deadly diseasecalled eternal bleeding. which causes the infected to loses the ability to heal wounds and cuts and lacerations begin to form on the skin causing the victim to bleed out within 24 hours.

After the dogs, it was the insects, which for the majority just increase their size to the size of a Chihuahua. Except for a few battles that grew to the size of a human and have mantis-like front legs, a pair of collapsible wings, and had a giant singular greenhorn on its head. These were Setlas male droids that follow the directions of there master a Setlas Queen. Which began to burrow out of the ground. When compared to the drones the Queen had a totally different anatomy structure. She was bigger than them, can't fly, is more armored than the drones, has six limbs, four of which make contact with the ground, the other two being used for digging and grasping prey. In addition, she has a long, segmented tail with a large pincer-like structure at the end. Setlas is famous for one thing spreading a plague called the thirst. Which the victim would become greatly dehydrated as the body begins removing a large quantity of water in any way possible, with diarrhea, sweating, vomiting, and peeing. Death occurs in two to three hours.

From the reptiles side, the majority just grew poisons fangs without any change in body size. And this poison was deadly I drop means instant death to anyone so unlucky to be bitten. Except for one group lizards that grew to the size of a house and had become almost chameleon-like from its independent moving eyes to its long and elastic tongue that was as long as its body. The only difference that this creature had with real-life chameleon besides its size was that it had powerful wings that allowed it to fly and that the fact it can turn invisible. Because of its similarity to chameleons these creatures a called Chameleos. which spread a disease called bloching. That causes every part of the victim's body to turn purple. Which is followed by vomiting purple blood, seizures, and insanity from the constant pain. Death comes slow to the victim that happens between two to three weeks.

And finally, the birds which simply grew teeth grew at minimal to the size of eagles and become so aggressive that they would simply attack any living thing that was not associated with the brown fog. All except one owl that grew to the size of a giraffe and has blue plumage. This thing is called a Malfestio and it spreads the deadly disease called the Sleep. Which causes the victim to sleep and never wake up.

All of these name creatures above are listed as S class threat level creatures in the supper natural world. As these carriers carry pathogens that currently has no cure and with a mortality rate of 90 to 95 percent. Why are these dangerous creatures appearing in Kuoh you ask? It was because he created them to do one thing and one thing only. To avenge the betrayal of his host.

" **MY MINIONS YOU ARE HERE FOR ONE THING AND ONE THING ONLY. AND THAT IS TO EXTERMINATE THE FALLEN THAT RESIDES IN THIS TOWN. NOW GO AND DESTROY THEM** " as soon as the voice stops every creature in the park than began marching to the current location of the fallen guided by the fog.

* * *

 **Fallen angle headquarters abandoned church**

Back in the fallen lair the bitch was still laughing and celebrating a mission well done.

"really that morron didn't see that coming and you guys should see his face when I told him the truth. It was priceless. HAHAHAHAHAHHA"

"oh man, I wish I was there. I would like to see the face of despair of idiots like that. Really Raynare next time brings me to those type of missions." Said by a fellow fallen angle which looked like a young blond child in a Gothic Lolita attire.

"maybe next time Mittle, but enough about that. Hey, Kalawarner how about you did you killed your target as well? " Raynare ask a fellow angle that was a tall and buxom woman with long, navy blue hair that obscured her right eye and brown eyes. Her attire consisted of a maroon, trenchcoat-like top with a wide collar, a matching miniskirt, and black heeled shoes.

"what do you think? Of course, I killed him too. It was so easy it was like shooting fish in a barrel." Kalawarner said as she was about to grab a nice cold beer.

"ohhh pass me one Kalawarner" the goth loli ask.

"isn't it too early for you to drink Mittel," Kalawarner said with a mischievous smile.

"Gezz not this again you know we are of the same age." Mittel than pouted. Making all three of them laughing joyfully. With the other stray priest and other fallen angels also enjoying the relaxing atmosphere.

Which was going to be destroyed soon? Very soon indeed.

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Well that's about it for now

Hope you enjoy.


	2. Chapter 2

**I don't own high school DXD or monster hunter world.**

 **Chapter 1: the stench**

* * *

 **The underworld: demon lords office**

It has been six months since the sleepy city of Kuoh was engulf by the mysterious smog. And the effects of the exposure is not pretty, either for the humans and the supernatural. As it has carved out an area filled with decay. As the local flora and fauna were mutated beyond recognition by its human inhabitants. Which was covered up by the supernatural world as mirages or hallucinations as an effect of a huge gas leak somewhere in the city. Which brought a city which evacuation and a no crossing perimeter was made around it.

Which was a good thing as there were some reports that the mist had some effects on humans that could lead to similar mutations as the animals. Which was now haunting the minds of the current Lucifer and Leviathan. As before the mist rolled in both of their favorite siblings were attending a school in that city. And if they didn't feel that ominous power surge and contain it who knows what real damage could happen in the human world.

"Sir here is the daily report of the situation of Kuoh" a soldier handed the demon lord the report.

"thank you for your hard work" the red devil smiled and read the report only to have his smile flip upside down.

'*sigh* no change again today, either from the expedition teams or the containment team.' The demon lord just massages his template as he was at a loss what to do.

'we can't use our magic in the mist and any special abilities either from sacred Gears or racial abilities are also negated. Limiting our strength to that of a normal human.' With a sigh, he dismisses the soldier and resumes his other duties as the demon lord.

"*knock**knock* Big brother are you here?" said by a familiar voice that instantly brought the worried king out of his sorrow.

"yes, ria-tan I am here!"

"seriously stop calling me that! Also *sigh* you should take a break you look horrible." Said the younger sister of the demon lord as she saw his brother with bags in his eyes and messy hair.

"no no, I still need to do my work aft-" before the demon lord could finish the young girl barge in and slam her hands on the table.

"NO BUTS! You have been working yourself to death ever since the Mist incident! Everbody from mom, dad and even your son Millicas is worried sick! So you either come home this instant or me and Grayfia are going to drag you there right here and right now." The red demon lord than saw his wife in a maid uniform carrying some rope and the look that every man fears. The face of a piss of wife.

"OK I will go home!" instantly Lucifer got up from his desk and darted back to his quarters.

"*sigh* seriously I wish he wouldn't make us worry this much. Thank you for coming to Lady Rias." The maid said while putting away the rope.

"He really is troublesome, but to think that he would beat himself this much."

"can you blame him after all he was only able to get you and Akeno-san out of there alive. While the others…." The maid just stops and bit her lip.

To this, the young heir teared up a bit "But it's not his fault that Kiba, Koneko, and Gasper are gone. Its all on me I failed them as a king that why they are not here. It's all my fault!"

"Lady Rias that is exactly why lord Sirzechs it beating himself up. As he couldn't do anything to stop that beast from killing them. "

"But-but it's not his fault! That mist made us unable to use our full strength. And if wasn't for his and lady Serafall gut feeling me and Sona would be dead."

"*sigh* I know that and so does he. But he still couldn't forget how much you cried during their funeral" the maid that walk away to her master side.

* * *

 **Conference room.**

"How long are we going to let this menace keeps a hold of our territory!" an elder scream frustrated at the static situation at Kuoh.

"But what can we do Magic is useless while we are inside of it and any attack we from outside the mist is instantly negated."

"Not to mention the terrain has changed thanks to the many elder dragons that come there to rest! Why just the other day a (Dalamandur)* came from a pocket dimension and crash straight into it."

"that not the only thing that the mist attracts many scavengers from every realm they also congregate and for some reason they are not affected by the mist. Its as if those beast are welcome in that repulsive place."

And much more chatter continued from the elders of the demon world which were being silenced by a black twin tail women that so happen to be one of their leaders.

"That's Enough! We are not here to squabble like children. But to get an update on the situation." She then looked at the devil that was leading the expedition force Sairaorg Bael.

"thank you for that lady Serafall, but unfortunately there is not much to report except that we found a new area in Kuoh."

"new area?"

"yes, a new area where according to the old maps of Kuoh was once the park. But now was covered in crystals that are filled with power. " he then presented the crystals to the elders and the demon lord.

"what is this crystal!"

"its filled to the brim with natural energy!"

"just touching them fills me with much power!"

"OHHHHHHHHHHHHHHH what power!"

Looking at the elder's attics the queen had to put them in line again "order order! Sairaorg continues."

"Thank you, after we found this area and explored it we found a blue cocoon, and as we were about to investigate were stopped by an elder dragon that I have never seen." The young man than pull up a hologram of the dragon.

And what the elders saw made them white as a ghost. As what they saw was a blue European style dragon that controls blue flames and had six red eyes on his head, which still hunted their dreams to this day.

"Xenojiva"

"NO not that monster!"

"but if he has appeared that means that that monster has returned!"

"NONONONONONONNONONO"

"one of the four riders of the apocalypse Val Hazaak has returned!"

"Order order!" Serafall trine to regain control but it was wasted effort as they were consumed by fear.

This reaction did spark an interest to the younger devils in the room including the queen herself. Sure they have heard about the four riders. But are they that scary? Is what they think. The elders that saw the young ones innocent felt jealous. As they don't know the first thing about what is really like to feel true fear.

* * *

 **Kuoh park.**

Once this place was filled with smiles and greenery. But now it has been transforming twice into a maze of gems. That was filled with the natural energy produce from the decay of the many elder dragons that came here. And lie deep within it lies Issei still in his deep sleep after his date with that traitorous fallen angel. And guarded by Xenojiva one of Val Hazaaks most loyal servants.

"Its been six months since we took over this town and boy time sure flies!" the dragon said clearly bored with his guard duties.

"But soon – very soon both master and that kid will emerge and this party will get started! But until than Mann I am borrrrred."

And then he heard a cracking sound and saw that the perverts crystal was about to shatter. This brought a smile to the dragons face as he knows that he was about to serve his old master again. And he got his wish as the cocoon shattered and he saw his master host alive and kicking.

"so kid what do you think of your new powers?" Xenojiva ask/

Issei looked at the dragon and smile "It feels amazing."

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Thanks for reading

if you want to know what a Dalamandur and Xenojiva

wiki/Dalamadur

wiki/Xeno%27jiiva


End file.
